Annals of the Transvaal Museum. 
69 
amongst the South African (south of theiZambesi and Cunene Rivers) land 
vertebrates ; but a rigid statistical inquiry of this kind may often prove 
very misleading, for there are a number of genera (Zonurus, Gerrhosaurus, 
Pachydactylus) which have each many species the majority of which are 
confined to South Africa, but as one or two outlying species happen to 
have crossed the border the genus has no title to be called peculiar, and 
yet the evidence of such genera is clearly of considerable import ; and, 
again, the genera which occur only in South Africa and in Madagascar are 
also misplaced in such a simple statistical scheme. But, as a matter of fact, 
this method would have led to a more correct conclusion had the author 
adhered to the Cape region as previously defined by himself. 
It is not possible for me to say to what extent the distribution and 
affinities of the other South African land vertebrates is in accordance with 
the conclusions based only on the study of the lizards — but probably it 
will be found that every group of vertebrates resolves itself into two 
sections representing the ancient and the new faunas — and as for the 
invertebrates it is hardly to be expected that many groups distribute them- 
selves according to vertebrate regions. However, Mr. Distant, from 
consideration of the Rhopalocera, is disposed to accept Sclater’s Cape region, 
but suggests that Somaliland should also be included (A.M.N.H. 7.1.47). 
Zoological regions have no absolute value and apply only to certain 
groups, seeing that the facilities for distribution vary immensely in the 
animal kingdom and that different groups of animals have arisen during 
different geological periods, and since their origin have been subjected 
to a great diversity of changes : and indeed a zoological area is chiefly 
interesting to the zoologist as a datum bearing on the history of the 
groups which conform to that area. 
The Zoological Sub-regions of South Africa. 
The available data are still insufficient to deal at all thoroughly with 
this subject, but the broad facts of the matter are as follows : a western 
portion comprising Angola, German south-west Africa, west Cape Colony, 
and the Karroo, has a very characteristic fauna abounding in types which 
are structurally adapted for life in arid and sandy regions ; an eastern 
portion, including German East Africa, Portuguese East Africa, British 
Central Africa, Rhodesia, low veld Transvaal, Zululand, Natal, and the 
eastern portion of Cape Colony, together with a part of the southern 
coastal strip, has also a distinct fauna. Between these two areas are 
included the Orange River Colony and the high and middle veld portion 
of the Transvaal, the fauna of which is more nearly allied to the western 
area though it is very much poorer in deserticolous types than is any 
portion of that western area. I believe, therefore, that in the southern 
portion of our sub-continent that extensive range of high mountains, the 
Drakensberg, marks the boundary between the eastern and western sub- 
regions, but it should be clearly understood this is not an absolute boun- 
dary for every species ; northwards there is no natural boundary to 
separate the two areas but, nevertheless, Angola and German East Africa 
have faunas sufficiently distinct but no doubt with some overlapping. 
The more characteristic fauna of the western region is as follows : — 
All the South African species of Eremias, and of Scapteira, the South 
African group of six species of Mabuia, including trivittata , occidentalism 
etc., the geckonid genera Ptenopus, Palmatogecko, Chondrodactylus, Rhop- 
tropus, and Colopus, the genus Cordylosaurus, and the species Amphisbaena 
quadrifrons Monopeltis capensis , Typhlosaurus lineatus, and Chamcteleon 
